It is desirable to treat water before it can be utilized in such applications as recreational swimming, bathing in hot tubs, drinking water, and also industrial uses such as cooling tower systems which employ large quantities of water. Chlorine has been used as the most common chemical for treating confined bodies of water to fight microorganisms such as bacteria which can contaminate the bodies of water and make them unsafe for contact by humans.
Modern systems for treating water, particularly recreational swimming pools, use dissolvable tablets as a chlorine source, such as calcium hypochlorite tablets. Such dissolvable tablets represent a convenient way to treat the water in swimming pools and spas.
In treating confined bodies of water such as swimming pools or hot tubs, regulation of the amount of chlorine added to the body of water is an important consideration. The addition of too little chlorine may result in the failure to eliminate sufficient numbers of harmful microorganisms. The addition of too much chlorine may result in adverse effects upon swimmers or bathers. Consequently, a chlorinator must be able to adjust the concentration of chlorine added to the body of water. In addition, in the context of a residential swimming pool, the chlorinator must require little maintenance. Further, because concentrated chlorine is toxic, the chlorinator must be safe to operate and maintain.